U.S. Pat. No. 5,252,650 teaches the use in a rubber of an alkyl (C.sub.12 -C.sub.22) esters of a mixture of fatty acids. The esters are useful as a total or partial replacement for extender or processing oil.
U.S. Pat. No. 5,227,425 teaches a thermomechanical mixing step of a rubber compound containing a sulfur containing organosilane wherein a rubber temperature of between 130.degree. C. to 180.degree. C. is maintained for a time period between 10 seconds to 20 minutes followed by addition of the vulcanization system at a lower temperature. It is believed that the thermal treatment during mixing promotes the sulfur linkages in the sulfur containing organosilicon compound to cleave forming bonds to the rubber and concomitant reaction of the alkoxy groups with the silica.